feat(web): finish RE 5000PBR lesson video and fix non-ASCII GLB import

- Add 11:07 Chinese-narrated lesson video, VTT, poster and 13 chapter screenshots.
- Regenerate 20-render WebGL2 matrix and 15 operation captures on RTX 4060.
- Fix WASM staging for non-ASCII import filenames (猴头.glb); rebuild web_engine.
- Harden lesson video recording pipeline; fix stale lesson-link E2E selector.
- Add RE PBR derived libraries, lesson page, evidence and status report.

Co-Authored-By: Claude Code <noreply@anthropic.com>

re/5000PBR精简版/blender_assets.cats.txt

@@ -0,0 +1,9 @@
+# This is an Asset Catalog Definition file for Blender.
+#
+# Empty lines and lines starting with `#` will be ignored.
+# The first non-ignored line should be the version indicator.
+# Other lines are of the format "UUID:catalog/path/for/assets:simple catalog name"
+
+VERSION 1
+
+96375bf8-9863-4327-8ff9-b72a50135728:砖:砖